The present invention relates to a method and apparatus for making a rotation-symmetrical gear member.
Gear members of a type involved here are used, e.g., in the automobile industry, for application as so-called starter rings. Currently, the manufacture of such a gear member is realized by forming from a circular blank a cap-like structure, which includes a concentric sidewall extending substantially in axial direction. A ring provided with outer teeth is welded to the outside of this sidewall, typically in the peripheral region of the sidewall, whereby the height of the ring in axial direction is smaller than the height of the sidewall. The resultant free zone of the sidewall is required for operation of sensors or other functional components. It is also known to provide in the sidewall functional window-shaped punchings in the free zone.
This conventional manufacturing process of such gear members suffers, however, significant shortcomings. For one, the manufacture is very complicated, as a consequence of, in particular, the required welding works. Furthermore, the texture of the used material, typically steel, always changes as a result of welding. This may adversely affect the material strength so that the service life of such a gear member is reduced. Moreover, the welding operation results in heat-based deformations that require in part an aftertreatment. Of course, this significantly interferes with the desire for an optimized manufacturing process.
The complexity of the conventional manufacturing process is also detrimental in situations in which gear members should be fabricated as a production article on a large-scale.
It would therefore be desirable and advantageous to provide an improved method for making a gear member, which obviates prior art shortcomings and enables a production of a gear member in a more simple, cost-effective manner and yet improved quality.